WASHINGTON – A U.S. State Department investigation has concluded that there was no conflict of interest in the contractor that conducted the final environmental assessment study into the Keystone XL pipeline.

The report by the Office of the Inspector General puts to rest allegations by environmental groups that contractor Environmental Resources Management Inc. (ERM) didn’t disclose that it had worked with Keystone’s promoter Calgary-based TransCanada Corp.

Environmentalists immediately denounced the report as a whitewash.

“The Inspector General Report raises more questions than it answers,” Erich Pica, president of Friends of the Earth, said in a statement.

He added that the report “reveals errors in the state departments process for vetting conflicts of interest.”

TransCanada said in a statement the reports “confirmed the integrity and independence of the state department’s contractor hiring and review process.”

The state department had previously done its own investigation and found there was no evidence its conflict of interest guidelines had been breached. The General Accounting Office has recently initiated a third investigation.

Bill McKibben, the founder of the environmental group 350.org, which opposes Keystone, said the report essentially reveals that the “whole process stinks.”

“The real scandal in Washington is how much is legal,” he told journalists.

The Inspector General’s report concluded that the state department “substantially followed its prescribed (conflict of interest) guidance and at times was more rigorous than that guidance.”

U.S. President Barack Obama told a governors convention this week that he expects to rule on the pipeline in a “couple of months.”

Obama has said his decision will be largely based on whether the Keystone XL will substantially add to the danger of climate change. The EMR report concluded that it would not.

The Keystone XL will transport oil from Alberta’s oilsands and the Bakken oil fields in Montana and the Dakotas to Texas Gulf Coast refineries.